The invention relates to a controller for a multi-voltage on-board power supply system in a vehicle and a method for operating a controller for a multi-voltage on-board power supply system in a vehicle.
Multi-voltage on-board power supply systems are occasionally installed in vehicles, such as automobiles, trucks, trains and the like. A multi-voltage on-board power supply system normally comprises a first subsystem which is operated at the first supply voltage, and a second subsystem which is operated at the second supply voltage. In particular, the 12 V subsystem and the 48 V subsystem for automobiles are known in this context.
In order to control a component, for example a pump, which is operated by one of the two subsystems or by both subsystems, a controller is normally provided which comprises a first control module and a second control module. The first control module is normally designed for operation at the first supply voltage of the multi-voltage on-board power supply system, and the second control module is normally designed for operation at the second supply voltage. For this purpose, the first control module is connected via a first supply path to a first supply voltage connection of the controller and/or to a first around connection of the controller in order to be supplied with current at the first supply voltage. The same applies accordingly to the second control module which is connected via a second supply path to a second supply voltage connection of the controller and/or to a second ground connection of the controller in order to be supplied with current at the second supply voltage. Voltage transformers can be provided in both supply paths so that a respectively transformed supply voltage is fed to the control modules.
The two control modules can be interconnected via a control signal path in order to exchange control signals with one another.
One problem with a generic controller for a multi-voltage on-board power supply system in a vehicle is that transient currents can occur within the multi-voltage on-board power supply system, for example in said control signal path, which can damage or destroy units of the multi-voltage on-board power supply system, in particular units of the controller. In addition, at a constantly applied first supply voltage and second supply voltage, leakage currents can occur, facilitated, for example, by electrochemical migration (humidity), which can similarly result in damage to the multi-voltage on-board power supply system, in particular to the controller for the multi-voltage on-board power supply system.